Technical Field
Example embodiments relate to semiconductor memories and, more particularly, to nonvolatile memory devices and programming methods thereof.
Discussion of Related Art
Semiconductor memory device are memory devices implemented using a semiconductor such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), and indium phosphide (InP). In general, semiconductor memory devices are classified into volatile memory devices and nonvolatile memory devices.
Volatile memory devices lose their stored data when their power supplies are interrupted. Nonvolatile memory devices may include a static RAM (SRAM), a dynamic RAM (DRAM), and a synchronous DRAM (SDRAM). Nonvolatile memory devices retain their stored data even when their power supplies are interrupted. Nonvolatile memory devices may include a read only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable and programmable ROM (EEPROM), a flash memory device, a phase change RAM (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), and a ferroelectric RAM (FRAM). Flash memory devices may be classified into NOR-type flash memory devices and NAND-type flash memory devices.
In recent years, a semiconductor memory device having a three-dimensional array structure has been studied to increase the integration density of the semiconductor memory device. In a three-dimensional array structure, vertical memory cell strings are connected to a substrate. Vertical memory cell strings may be connected to a common source line through the substrate. During a program operation, leakage current may be generated at a common source line junction. Due to the leakage current, an abnormal disturbance may occur between the vertical memory cell strings.